Vibration damper



Oct. 26, 1937. E. o. scHJoLlN VIBRATION DAMPER Filed June 18. 1936Patented Oct. l26, 1937 UNITED STATES PATENT OFFICE VIBRATION DAMPER yApplication June 18, 1936, Serial No. 85,843

Claims.

This invention relates to the transmission of power from an internalcombustion engine and has particularly to do with a device to dampen thevibrations of the power shaft driven by the 5 engine and connected tothe transmission of an automotive vehicle. s

In conducting experiments with a rear drive engine on anautomotivevehicle, due to the fact that it was .necessary to compact thedrive mechl0 anism from the engine to the rear drive axles, 'atransmission was designed in which the drive shaft passed through ahollow quill of the transmission and drove the quill through theintermediary of the clutch outside the transmission housing. The driveshaft inside the quill although made of a good grade of steel was foundto be quite flexible becauseof its relatively small diameter. This driveshaft is shiftable as well as rotatable and has a tongue and grooveorscrew. driver connection with the end of the crankshaft. The shaft wasmade shiftable so that it could operate the clutch. In operating therear drive vehicle, the engine used was a two-cycle engine having fourcylinders, and consequently for each rotation of the crankshaft therewould be four impulses transmitted to the drive shaft and necessarilyfour twists to the shaft. Due to the resiliency of the shaft, thesetwists would first lag behind the crankshaft and then as the twistsunwound, would send the shaft ahead of the-crankshaft so that there wasan alternate twisting back and forth of the shaft, which twistingoccurred four times for each crankshaft revolution. Where the speed ofthe crankshaft is high, it can readily be appreciated that the number oftwists to the crankshaft are excessivelyhigh. It was found that the,crankshaft heated, and the heating became so bad that eventually itwould warp and break. It was thereforewnecessary to devise some meanssuccessfullyl to dampen the vibrations or twists of the shaft so that itwould have smoother running and would not heat. 'Ihe transmission towhich theshaft is applied and the clutch interrelated therewith, areshown and described in my ca -pending application, S. N. 55,626, filedDecember 21, 1935. The damping of the shaft was accomplished byproviding a collar on the drive shaft and equipping the adjacentmechanisml with faces having friction materialthereon, so

that the friction between the collar and the friction surfaces willovercome the impulses transmitted to' the drive shaft by the crankshaft.'Ihese friction surfaces are pressed against the collar by means of theclutch operating fork and struction, the section being taken on the linel0 2-2 of Figure 1.

Figure 3 is a'detailed view on the line 3-3 of Figure 2 showing themanner of mounting the Belleville washers on the transmission shaft orquill. 16

Figure 4 is a diagrammatic view showing the elementary way of balancinga shaft.

Referring to the drawing, the numeral 2 indicates an internal combustionengine of any suitable type. In the present instance the en- 20 gine isa four cylinder, two-cycle engine having U cylinders. 'Ihe cylinderhousings are indicated at 4 and the crankcase at 6; the crankcase havingthe -crankshaft 8 journaled therein in the bearings 9. 'I'hecrankshafthas the ywheel I8 25 which has formed integral therewith, agear I2 used to drive the auxiliaries of the engine such as the fuelpump,`distributor, blower, etc. The flywheel is provided with a slot(not shown) in which there is yslidably received a tongue IB on 30 ftheend of the slidablev and shiftable shaft. I8. The shaft I8 passesthrough the transmission 20 and has secured on its outer end the drivingmember 22 of a cone clutch indicated as a whole at 24. the usual hubsplined tothe end of the shaft I8 and -is held thereon by a nut 30threaded on the end of the shaft. The driven member of the clutch isindicatedfat 44 and `comprises a web 46, the outer steel ring 48 and thehub 58. The ring r40 48 has the peripheral teeth 5I to enable thestarting motor (not shown) to rotate the clutch to start the engine 2.In order to form a pulley to drive the fan belt 52, an additional plate54 is formed to the shape shown in Figure l and is 45 suitably securedto the web 46 to form a V groove 5B to receive the belt 52. The usualclutch lining is shown at 65.,

'Ihe hub 50, theinner edges of the web 46, and the plate 54 are securedtogether by means of the 50 rivets 66.

'I'he transmission case is indicated at 68 and is provided with theendbearfngs lll and I2` in which there is turnably mounted the shaft orquill 14, the shaft 14 in turn forming a bearing for the 55 The drivemember 22 is provided with ,35

I -witlr the shaft 'I4 is the low or first speed gear 16 and reversegear 18. The shaft has the splined portion 80 on which there is slidablymounted the gear 82, adapted to mesh with the internal teeth 84 of thegear 86. The gear 86 has a hub 88 adapted to turn in the bearings 12 and80. By shifting the gear 82 into engagement with the teeth 84, a directdrive of the vehicle is accomplished by driving the gear 82 on the shaft84 parallel with the shaft 14.: The shaft 94,has the gear 96 at its endwhich gear meshes with an idler J gear 88 which is connected to theusual ring gear of the differential (not shown) To drive in first speedthe gear I 00 is shifted to the right to mesh with the gear 16 and forreverse the gear |00 is shifted to the left to mesh with an idler gear(not shown) which in turn is driven from the gear 18.

-The second speed is accomplished by shiftingvthe gear 82 to the rightto mesh with the gear |02. ,s

The driving member 22 'of the clutch 24 'is also bearing cage |05 of theball bearing |01, to slide the shaftl8 to the right (Figure 1) againstthe tension-of' the Belleville washers 06. The fork ``-|-04`has its endabutting thestationary pin |09 which serves as a fulcrum for the shifterfork.

Whenthe clutch fork |04 is operated, it will comreleased, the Bellevillewashers |06 will expand to push the shaft I8'toithe left to causethe-clutch member 22 to engagethe clutch member 44.

to keep the clutch in engagement. The Belleville `washers |06 aresecured to the shaft 14 by the squaredconnection shown at I I9 in Figure3.

Referring to Figure 2, the shaft I8 has formed thereon, the collar `I20'having its side faces machined.A This collar is preferably an integralpart ofthe shaft. The Belleville washers |06 have the plate |22 at theleft thereof, the plate having a shoulder |24 on which there rests theinner race l The inner race |26 i's suitably rounded to' receive theballs |28, while theouter race |30 is likewise suitably rounded andfits-over the balls |28. A retainer |32 having its inner end inwardlyanged as at |34 around the I 26 of. the ball bearing |01.

inner race |26, holds the two races together. The retainer |32 has ashoulder |36 at its free end and over the shoulder |36. the tines of thefork are received.

The inner race |26 has the annular angel |38 formed thereon, which angeextends on the machined side of the collar |20 adjacent the engine. Thisiiange has a tin facing |40 to act as a `friction material to retard'the vibrations of the shaft I8, due to the impulses from the crankshaft.At the opposite face of the collar I 20 or at the side facing theclutch, there is interpositioned between the plate |22 and the-collar|20, the floating washer |42. This washer ts over the shoulder |46 onthe shaft and has a copper-lead friction facing |48 where it abuts theside of the collar |20. Inasmuch as the Belleville washers constantlywill urge the washer |42 against the side face of` the collar |20, thecopper-lead friction facing will act to retard the vibrations of theshaft due tothe impulses of the engine.

In Figure 4 there is shown in a general way, 'a

TheV -Belleville washers |06 therefore, tend constantly driving shaft I8of the motor. Integrally formed mass M lsurrounding a shaft S,thezvi'bration of' lthe resistance offered by the friction surfaces,

and as the impulse stops, the energy stored `in the spring will causethe mass to. move against the frictional resistance to dampen thevibration. The springs themselves, when they are being compressed, willresist the vibration because of the inertia offered by the mass M. Inthe invention .shown on thexdrawing, the clutch 24 forms the mass M,nwhile the shaft I8 itself takes the place act as the springs whichcompressthe friction surfaces against the mass M. When the engine 2gives an impulse to the crankshaft 8, this im- .pulse will betransmitted to the s haft I8, but due to the friction caused by thepressure of the Belleville washers on the floating washer I 42 and thefriction surface |48, there will be increased friction created whichwill Aproduce work. 'This amount of friction and work will be resistedby the friction surfaces. |48. When the clutch is of the coil springs C.The Belleville washers |06 N the shiftable member of the clutch and inthis being disengaged the pressure of the fork |04 ent resiliency of theshaft, plus the frictional resistance offered by the work caused by thefriction between the sides of the collar and the friction surfaces and|48. When the vehicle is in motion and the transmission is in use, the

shafts I8 and 14 will rotate at the same speed and in the samedirection, therefore should the shaft I8 twist or tend to run ahead ofor behindthe shaft 14, this motion will be communicated through theclutch to the shaft 14 and from the shaft 14 to the collar |20 throughthe Belleville washers and the friction surface |48, where it will becounteracted to suppress the twist or vibration.

I claimi 1. In a vibration damper for the flexible rotatable shafttransmittingthe power from an engine to a transmission through aclutch-said flexible shaft being shiftable to cause the disengagement ofthe clutch-and being surrounded by a shaft-of the transmission, aplurality of spring means free of the fiexible shaft and secured to thetransmission shaft and constantly urging the clutch in engaged position,means adjacent the springs to enable the shifting of the shiftable shaftto compress the springs and disengage the clutch, and friction meansinterrelated with the shifting means and the springs to dampenvibrations in the flexible shaft due to impulses of the engine.,

2. In a vibration damper for the `flexible 'rotatable shaft transmittingthe power from an engine to a transmission through a clutch, saidilegible free of the exible shaft and secured to the transmission shaftand constantly urging the clutch in engaged position, means adjacent thesprings to enable the shifting of the shiftable shaft to compress thesprings and disengage the clutch, an

interengaging friction means on the shaft and between the shaft and thesprings to dampen the vibrations of the exible shaft due to impulses ofthe engine.

3. In a. vibration damper for a exible rotatable shaft driven from oneof its ends, a hollow shaft surrounding said flexible shaft, a clutch atvthe end of said exible shaft, one member of the clutch connected to thehollow shaft and the otherY member connected to the flexible shaft,means at the driven end of the flexible shaft constantly urging theclutch into engaged position, means at the driven end of the flexibleshaft to shift the shaft to disengage the clutch, and a friction meansbetween said two means to dampen vibrations of the Shaft.

4.' In a vibration damper for a exible rotatable shaft, a mass at oneend of the shaft, means to drive the shaft from the other end, a meansto shift the shaft, means constantly urging the mass to a definiteposition, means interconnecting the mass and the last named means, andfriction surfaces between the shifting means and the urging means todampen the vibrations of the shaft caused by the driving mea-ns.

5. In a vibration damper means for a rotatable shaft, a collar rigidwith said shaft, springs surrounding said shaft for pressing against oneface of said collar, a shifting cage on the other side of the saidcollar and mounted on said shaft, a friction means between said collarand said springs and between said collar and said cage to dampenvibrations in the shaft.

6. In a vibration damping means for a rotatable exible shaft, a collarrigid with the shaft, a shifting cage on one side of the collar,friction material on the cage, a floating'washer on the other side ofthe collar, friction means between the washer and the collar, and meansto press the cage and the washer against the collar to produce frictionto dampen the vibrations of the Shaft.

7. In a vibration damping means for a rotatable exible shaft, a collarrigid with the shaft, a second shaft surrounding the,flexible shaft, aplurality of springs on the end of the second shaft and turnabletherewith, said springs mounted adacent the collar on the rst shaft, aplate between the springs and the-'conan a washer between the plate andcollar friction means on the washer between the washer and the collar, abearing cage on the other side of the collar and extending around thecollar and against the plate, said cage adapted to` be moved to depressthe springs, a friction means between the collar and cage, said frictionmeans damping the vibrations of the shaft.

8. In a vibration damper for a rotatable shaft, a collar rigid with theshaft, a floating washer on one side of the collar, a friction facing onthe washer between the collar and the washer, a cage around the shaftand having a face abutting the other side of the collar, a frictionfacing on the abutting face, and means to press said friction facesagainst the collar to dampen the vibrations in the shaft.

9. In a vibration damper for a rotatable, shiftable shaft, a collarrigid with the shaft, a floating washer on one side of the collar. afriction facing on the washer between the collar and the washer, a platerotatable and shiftable with the shaft on the other side of the collar,friction facing on the plate side abutting the collar, and means toforce said plate and washer against the collar to cause friction todampen the vibrations in the shaft.

10. In a vibration damper for a rotatable, shiftable and flexible shafthaving a clutch connected thereto, said shaft being driven from one endby an engine and-having one member of the clutch secured to the otherend, ashaft surrounding said shiftable shaft and havingthe second memberof the clutch secured thereto, a collar rigidl with the exible shaft, aplurality of Belleville washers secured to the second shaft, meansbetween the washers and the collar to cause the washers to act thereonand tending constantly to keep the clutch in engagement, a frictionfacing between the collar and said means, a bearing cage surrounding thefirst-shaft and abutting against said means and adapted to be moved tocompress the washers and to shift the rst named shaft to disengage theclutch, and a friction facing between said cage and the other side ofSaid collar, said friction facing damping the vibrations in the saidshaft. i

ERIC OLLE SCHJOLIN.

